Genetic polymorphism in Methylenetetrahydrofolate Reductase chloride transport protein 6 (MTHFR CLCN6) gene is associated with keratinocyte skin cancer in a cohort of renal transplant recipients

Background

Renal transplant recipients (RTRs) are at increased risk of keratinocyte cancer (KC), especially cutaneous squamous cell carcinoma (cSCC). Previous studies identified a genetic variant of the Methylenetetrahydrofolate Reductase (MTHFR) gene, C677T, which conferred a risk for diagnosis of cSCC in Irish RTRs.

Objective

We sought to find further genetic variation in MTHFR and overlap genes that may be associated with a diagnosis of KC in RTRs.

Methods

Genotyping of a combined RTR population (n = 821) from two centres, Ireland (n = 546) and the USA (n = 275), was performed. This included 290 RTRs with KC and 444 without. Eleven single nucleotide polymorphisms (SNPs) in the MTHFR gene and seven in the overlap gene MTHFR Chloride transport protein 6 (CLCN6) were evaluated and association explored by time to event analysis (from transplant to first KC) using Cox proportional hazards model.

Results

Polymorphism at MTHFR CLCN6 (rs9651118) was significantly associated with KC in RTRs (HR 1.50, 95% CI 1.17–1.91, p < 0.00061) and cSCC (HR 1.63, 95% CI 1.14–2.34, p = 0.007). A separate SNP, MTHFR C677T, was also significantly associated with KC in the Irish population (HR 1.31, 95% CI 1.05–1.63, p = 0.016), but not American RTRs.

Conclusions

We report the association of a SNP in the MTHFR overlap gene, CLCN6 and KC in a combined RTR population. While the exact function of CLCN6 is not known, it is proposed to be involved in folate availability. Future applications could include incorporation in a polygenic risk score for KC in RTRs to help identify those at increased risk beyond traditional risk factor assessment.

A retrospective review of pregnancies on biologics for the treatment of dermatological conditions

Psoriasis often first presents in young adulthood, with the average age of diagnosis in women being 28 years, thus in the prime reproductive years. In addition, approximately 50% of pregnancies worldwide are unplanned. Although biologic therapies have revolutionized the treatment of moderate-to-severe psoriasis, there are no controlled studies of biologics in pregnant women. The increasing use of these agents in women of childbearing age highlights the need to further assess their safety during pregnancy. Postmarketing experience regarding the safety of these drugs is accumulating and being published, with largely reassuring results. We present our real-world experience of 17 pregnancies occurring in women on treatment with biologic agents for dermatological conditions to further add to the body of knowledge.

Demyelination during anti-tumour necrosis factor therapy for psoriasis

Anti-tumour necrosis factor (anti-TNF) therapies have been associated with neurological complications, including in rare cases demyelinating disease. It is currently unknown whether patients who have received more than one immunosuppressive agent or anti-TNF have a greater risk of demyelination. We report the case of a 37-year-old woman with psoriasis who presented with an acute episode of demyelination while on anti-TNF therapy. This case was complicated by the fact that progressive multifocal leukoencephalopathy was considered the likely diagnosis initially and was only definitively excluded by brain biopsy. This case demonstrates the difficulty establishing the correct diagnosis in patients with atypical presentations on immunomodulating therapies. We present this rare case of demyelination in a patient who received multiple immunosuppressive therapies to highlight this challenging clinical situation and discuss management with a literature review.